Reversing mechanism for explosion-engines.



No. 790,856. PATENTED MAY 23, 1905.

T. L. & T. J. STURTEVANT. REVERSING MECHANISM FOR EXPLOSION ENGINES.

APPLICATION FILED JUNE 11, 1903 5 SHEETS-SHEET l.

m'tmsas': Inw/ ans:

No. 790,856. PATENTED MAY 23, 1905. T. L. & T, J. STURTEVANT.

REVERSING MECHANISM FOR EXPLOSION ENGINES.

APPLICATION FILED JUNE 11,1903.

I 5 SHEETSSHBET 2.

Wilntssea: Int? n9:

5 2%. W 7 )2 J:, n

No. 790,856." PATENTED MAY 23, i905. T. L. & T; J. STURTEVANT. REVERSINGMECHANISM FOR EXPLOSION ENGINES.

APPLIUATIOH FILED JUNE 11, 1903.

5 SHEETS-SHEET 3.

VIII/Ill/ZH Ill/l Inventors;

vAr/ mtneases 2/1.

No. 790,856. PATENTED MAY 23, 1905.

v T. L. & T. J. STURTEVANT. REVERSING MECHANISM FOR EXPLOSION ENGINES.

APPLICATION FILED JUNE 11, 1903.

5 SHE ETSSHBET 1 No. 790,856. PATENTED MAY 28, 1905. T. L. & T. J.STURTEVANT. REVERSING MECHANISM FOR EXPLOSION ENGINES.

APPLIOA-TIOIT FILED JUH E 11 1903.

5 SHEETSSHEET 5.

P Nrrn STATES Patented May 23, 1905.

THOMAS L. STURTEVANT, OF QUINCY, AND THOMAS J STURTEVANT, OF VELLESLEY,MASSACHUSETTS.

REVERSING MECHANISM FOR EXPLOSION-ENGINES.

SPECIFICATION forming part of Letters Patent No. 790,856, dated May 23,1905.

Application filed June 11,1903. Serial No. 160,996-

To all 7/:7'1/0771, it inn/7] concern:

Be it known that we, THOMAS L. STURTE- VANT, residing at Quincy, andTHoMAs J. STURTEVANT, residing at VVellesley, in the county of Norfolkandv State of Massachusetts, citizens of the United States, haveinvented certain new and useful Improvements in Reversing Mechanism forExplosion-Engines, of which the following is a specification, referencebeing had therein to the accompanying drawings.

This invention has for its object to provide a simple mechanism wherebythe direction. of rotation of an explosion-engine may be reversed whendesired. It is well known to those familiar with this class of enginesthat when the electric current is shut off for the purpose of stoppingthe engine the engine will stop on a compression-stroke, for the reasonthat the power required for compressing the explosive gases in anengine-cylinder is so great that the engine comes to a halt on such acompression-stroke and immediately thereafter a rebound or slightreversal of the engine occurs, due to the elasticity of the compressedcharge. Now if an explosive mixture in the cylinder of the engine befired at the moment the rebound occurs the engine will get a powerfulimpulse in the reverse direction of rotation commencing with therebound, so that the engine will continue to run in such reversedirection when the sparking and exhaust devices are properly adjusted.

This invention therefore comprises means whereby an explosive chargewill be automatically ignited during the rebound occur ring whenstopping the engine, thereby revcrsing the engine.

In carrying our invention into effect wereferablyemploymanually-controlledmeans for changing the timing of thesparking and exhaust cams and simultaneously therewith for opening theswitch to break the electric circuit and for placing such switch in suchposition that it will automatically close the circuit and ignite thecharge at the rebound occurring after the engine is stopped on acompression-charge.

In the accompanying drawings, Figure 1 is a plan view of a four-cyclefour-cylinder explosion-engine embodying our invention. Fig. 2 is a sideview of the same, partly in vertical section. Figs. 3 and 4 aresectional detail views, to be hereinafter referred to, showing thesparking and exhaust cams, the switch, and portions of the reversingmechanism. Figs. 5 and 6 are detail views illustrative of the sparkingcams and the means for adjusting same. Figs. 7 and 8 are views showingthe reversing-switch device in different positions, these viewsillustrating said switch device as the same appears when looking at itin the direction denoted by the arrow 2 in Fig. 1. Fig. 9 is a detailview illus trative of the gearing and its connection with the secondaryshaft. Fig. 10 is a detail view illustrating a portion of the exhaustmechanism.

Referring to the drawings, 12 denotes the main shaft of the engineprovided, as usual, with a balance-wheel 13 and having suitable cranksconnected by pitmen 15 with pistons 16 in suitable oppositely-arrangedcylinders 17, one of which is shown in section in Fig. 2. 7 5 Theexplosion-engine herein shown is therefore of a four-cylinder type andis also of a four-cycle type in that an explosive charge in eachcylinder is fired at each alternate reciprocation of each piston. Eachcylinder is provided with an inlet-valve 18 and an exhaust-valve 19, theexhaustvalve being held to their seats by suitable springs, and theexplosive gases are in the present machine preferably fired byjump-spark devices 20, connected in suitable electric circuits(indicated by the wiring in Fig. 2) and supplied from a suitable sourceof electricity, as from a dynomo or from a battery 21. The severalcircuits referred to are in the present instance 0 connected with ajump-spark-coil box 23, containing tremblers of well known construction,such as are usually employed in jump-spark circuits; but any suitablemeans for supplying an interrupted or other kind of current may beemployed.

The main shaft 12 is provided with a spiral gear-wheel 24, meshing witha smaller spiral gear 25, mounted on a secondary shaft 26, rotating athalf the speed of the main shaft. Splined to the secondary shaft 26 torotate therewith are the exhaust-cams 27 for oper ating the levers 28,engaging the upper ends of the exhaust-valve rods 29. The shaft 26 isadapted to be shifted endwise inits bearings and is provided with aroller-stud 30, entering a spiral slot 31, formed in a sleeve 32, and towhich sleeve the spiral gear 25 is rigidly attached. The sleeve 32 isheld from endwise movement with the shaft 26 between suitable bearings33, and owing to the fact that the gear-wheel 25 is in. mesh with thelarger gear-wheel 24, so that said gear-wheel 25 will be held fromrelative movement, it results that when the shaft 26 is moved endwisethe spiral slot 31 in the collar 32 will cause a relative turningmovement of said shaft 26 and of the exhaustcams 27, splined thereto, sothat an endwise movement of said shaft 26 will cause a change of thetiming of said exhaust cams. The exhaust cams are restrained fromendwise movement with the said shaft by the stationary shaftbearingscontiguous to the ends of said cams. (See Figs. 3 and 4.) The shaft 26is also provided with a pin or roller-stud 34, entering a spiral slot 35in a sleeve 36, to which are secured the sparking cams 37 for closingthe several circuits at the proper times to effect the firing origniting of the compressed gases, each of said cams operating a movablecontact device or pin 38, which is forced against a stationary contactdevice or pin 39 when the circuit is to be closed. Thus when the shaft26 is moved endwise its torsional or turning movement will cause achange of timing of the exhaust-cams 27 and will also change the timingof the sparking cams 37, and. the turning or torsional movements ofwhich latter will be different from that of the exhaust-cams owing tothe pin and spiral slot connection of sleeve 36 with the said shaft 26.The sleeve 36, to which the sparking cams are fixed, will be held fromendwise move ment with the said shaft 26 by the box 40, which inclosesthe sparking cams and their contact devices. In other words, the saidbox will restrain the said cams from moving endwise with said shaft andthe cams being fixed to said sleeve will restrain the latter fromendwise movement. (See Fig. 4.) The normal working positions of thesparking cams may be regulated as may be desired by shifting the box 40to different positions, as indicated in Figs. 5 and 6, and inthese-different positions of adjustment of the said box 40 it may befixed in place by means of a slotted sector-post 41 and a nut or handwheel 42, engaging a stud 70, fixed to said box and entering the slot insaid post. The shaft 26 may be moved endwise in any suitable manner, butpreferably by a hand-lever 43, having a swiveled connection with saidshaft, as

will be understood from Figs. 2 and 3, so that the said shaft may freelyrotate, but may be moved endwise either during rotation or when at restby means of the manually-operated lever 43.

Attached to the shaft 26 are two frictioncones 44, surrounded by afriction-sleeve 45, to which is rigidly connected an arm 46, in whichare pivotally mounted two contact devices 47 and 57, the free ends ofwhich are normally pressed apart by a spring 48.

Attached to the frame of the engine is a standard 49, provided with anopening or slot 50, into which the contact devices 47 and 57 extendloosely in such a manner as to have a limited movement vertically.Supported by the standard 49 are contact-pins 51 and 52, carried bysprings 53, so as to be capable of more or less vertical movement. Thepins 51 and 52 are adapted to be forced into contact with each other bythe contact devices 47 and 57, as will be understood from Figs. 7 and 8,when the friction cones and sleeves are in either of the positionsdenoted in full and dotted lines in Fig. 2. Thus when the said frictioncones and sleeves are in the position shown by full lines in Fig. 2 thecontact devices 47 and 57 will be in the position denoted in Fig. 7 andthe circuit (grounded through the engine) will be closed through thecontact-pins 51. When, however, the shaft 26 is moved endwise toward theleft, Fig. 2, so as to move the friction cones and sleeve to theposition denoted by dotted lines in said figure, the contact devices 47and 57 will be moved to theright-hand end ofthe slot 50 with referenceto Fig. 8 (or the left-hand end of said slot with reference to Figs. 1,2, and 3) and the contact device 57 will be brought against the stop 54on the standard 49, so as to compress the spring 48. In other words,when the engine is running forward and the shaft 26 is rotating in thedirection of the arrow in Fig. 3 the contact devices 47 and 57 will belifted against the upper wall of the slot or opening 50 in the standard49, owing to the friction between the cones 44 and the sleeve 45, andwith which sleeve the contact devices 47 and 57 are connected, and thusif the shaft 26 be shifted endwise toward the left hand, Fig. 2, whilethe engine is running the said contact devices 47 and 57 will be heldagainst the upper wall of the slot or opening 50 until the engine isreversed at the rebound. This result is due to the friction between thecones 44 and the sleeve 45, which has a tendency to lift the arm 46,which is rigid with said sleeve and on which arm the contact devices orswitches 47- and 57 are pivotally mounted.

The shifting of the shaft 26 to the left, Figs. 1 and 2, opens theelectric circuit, owing to the removal of the contact device 47 from thepin 51, and the sparking device being thus interrupted the engine willsoon come to rest and will stop on a compression-stroke.

As the engine thus stops on a compressionstroke the elasticity of thecompressed charge will cause a rebound, which would normally be only aslight reversal of the engine; but in accordance with the presentinvention this rebound is utilized to ignite the compressed charge whenthe rebound occurs, and thus set the engine running reversely. The firsteffect of the rebound communicated through the shaft 26, thefriction-cones 44 thereon, and the friction-sleeve 45, sur rounding saidcones, imparts a downward movement to the arm 46, and thereby releasesthe spring-pressed contact devices 57 from the stop 54, and as soon assaid contact device 57 is released from its stop and is moved downwardinto contact with the lower wall of the slot or opening 50 the spring 48immediately forces said contact device or switch 57 beneath thecontact-pin 52 and closes the circuit, so as to ignite the compressedcharge. Thus when a rebound occurs the compressed charge will beautomatically ignited at the proper instant after the hand-lever 43 hasbeen moved to shift the shaft 26 endwise, this endwise movement of saidshaft changing the timing of the sparking and exhaust cams through themechanism heretofore described. l/Vhen it is desired to stop the reversemovement of the engine and set the same running forward, the hand-lever43 is moved from the position denoted in dotted lines to the positionshown in full lines in Fig. 2, thereby moving the friction-cones 44 andfriction-sleeve 45 from the position shown in dotted lines to theposition shown in full lines in said figure, as the shaft 26 is shiftedendwise, such movement of the said hand lever and of the said shaft 26moving the switch contact devices 47 and 57 from the position shown infull lines in Fig. 8 to the position partly shown in dotted lines inFig. 7, with the contact device or switch 47 against the stop 55 at thelower wall of the slot or opening 50, the said contact devices 47 and 57being, it will be understood, held against the lower wall of said slotor opening so long as the engine is running backward or reversely. Thisshifting movement of the contact devices or switches 47 and 57 shuts offthe sparkingcurrent, so that the engine will stop on a compressedstroke, and in thus stopping will rebound slightly or start to runforward, and such rebounding forward movement of the engine-shaft,communicated through. the sec ondary shaft 26, the friction-cones 44,secured to said shaft, the friction-sleeve 45, engaging said cones, andthe arm 46, rigid with said friction-sleeve, will lift the contactdevices or switches 47 57, so that the contact device or switch 47 willbe clear of the stop and will be forced by the spring 48 beneath thecontact-pin 51, thereby again closing the circuit, and as the exhaustand sparking cams will, simultaneously with the shifting movement of theswitch by the hand-lever 43, have been returned to their first positionsin proper timing for running the en gine forward the ignition of thecompressed charge, when the circuit is closed through the switch-contactdevice 47 and pins 51, will again set the engine running forward in thesame smooth and easy manner in which it was started running backward.

From the foregoing it will be understood that our invention comprisesmeans whereby, when a manually-operated device or lever is moved to shutoff the sparking-current for the purpose of stopping the engine, thecontinued movement of said manuallyop erated device will set the switchin such position that when the engine-shaft is slightly reversed by therebound always occurring in this class of engines after the engine hasbeen fully stopped, and which stoppage always occurs on acompression-stroke, the compressed charge will be automatically ignitedand the engine be set running in the reverse direction. Thus as therebound is in itself the commencement of the reversal of the engine, andas the compressed charge is igniterl at the rebound, so as to give apowerful impulse or acceleration to thereversemovement of the enginecommencing with the rebound, the reversal of the engine is effectedwithout any such sudden shock as would occur if a charge were ignitedfor the purpose of reversing the engine while the engine was stillrunning forward. Our invention therefore enables us to reverse anexplosion-engine and to start the same running in either direction bypower in a smooth and easy man ner without shock and without strainingthe machinery.

Having thus'described our invention, we claim and desire to secure byLetters Patent In an explosion-engine, the combination with a sparkingapparatus, of a manually-operated switch by which an electric circuitmay be opened to shut off the current, and automatic means, connectedwith the engine-shaft, whereby the circuit will be closed when a reboundoccurs at a compression-stroke, for the purpose of setting the enginerunning in a reverse direction.

2. In a four cycle explosive engine, the combination with a sparkingapparatus, of a manually-operated switch for opening the circuit, andwhich is so arranged that it may be manually set for automatic closing,and automatic means, connected with the engineshaft, whereby the circuitwill be closed when a rebound occurs at a compression stroke, for thepurpose of setting the engine running in a reverse direction.

3. In an explosion-engine, the combination with an electricsparking-circuit and a switch for opening and closing the same, of

automatic means for closing the circuit, when the current is shut off,at the instant of rebound on a compression-stroke; thereby positivelyreversing the working of the engine by continuing the reverse movementcommenced by the rebound.

4. In an explosionengine, a reversing mechanism comprising thecombination with an electric sparking-circuit and sparking and exhaustcams, of manually-controlled means for changing the timing of said cams,a switch, and automatic means whereby, at the rebound, on acompression-stroke and when the current is shut off, the switch will becaused to close the circuit and ignite the compressed gases; thuspositively continuing the reverse movement of the engine commenced bythe normal rebound.

5. In an ex losion-engine, the combination with an e ectric sparkingapparatus, of manual means for opening the circuit, automatic means,controlled from the rebound of the enginepiston, for closing the circuitand thereby igniting a compressed charge when a rebound occurs after theengine has been stopped, for the purpose of reversing the engine.

6. In an explosion-engine, the combination with an electric sparkingapparatus, of a manually-adjustable switch for opening the electriccircuit, and automatic means for closing the open circuit to ignite acharge when a rebound occurs on a compressionstroke, as the engine isstopped.

7. In an explosion-engine, the combination with the main shaft of theengine, of a longitudinally-movable secondary shaft geared thereto,sparking and exhaust cams mounted on said secondary shaft, a switch alsoconnected with said secondary shaft, means for shifting said secondaryshaft lengthwise, means for changing the timing of the said sparking andexhaust cams as the said secondary shaft is shifted lengthwise, andautomatic means for closing the circuit on a reversal of the saidsecondary shaft when a rebound occurs on a compression-stroke as theengine is stopped when the sparkingcur rent is shut off.

8. In an explosion-engine, the combination with an electric sparkingapparatus, and manually-adjustable means for changing the timing of thesparking devices, of a switch device for opening and closing thecircuit, and frictionally-operated automatic means for closing thecircuit to fire a compressed charge when a rebound occurs after the engine is stopped, thereby setting the engine running in a reversedirection commencing with the rebound.

9. In an explosion-engine, the combination with the main shaft 12, of asecondary shaft 26 geared thereto and mounted for endwise orlongitudinal movement, means for imparting a torsional or turningmovement to said shaft as it is moved longitudinally, sparking andexhaust cams connected with said shaft but restrained from longitudinalmovement therewith, so that turning or torsional movements of said shaftwill change the timing of said cams, an electric sparking apparatuscomprising an automatic switch carried by a part which is frictionallyconnected with said shaft, and which is longitudinally movabletherewith, and manual means for imparting a longitudinal or endwisemovement to said shaft to open the electric circuit; whereby, when thesaid shaft is shifted longitudinally or endwise manually, the timing ofthe sparking and exhaust cams will be changed and the automatic switchso set that when a rebound occurs after the engine is stopped thecircuit will be automatically closed and the engine set running in areverse direction.

In testimony whereof we afiix our signatures in presence of twowitnesses.

THOMAS L. STURTEVANT. THOMAS J. STURTEVANT. Witnesses:

W. H. ELLIs, L. H. STURTEVANT.

